Foot operated hydraulic pump



Dec. l5, 1953 G. W. MCLELLAN 2 662 475 FOOT OPERATEID HYDRAULIC PUMP Filed June 5, 1950 U N@ .Lal

BY 5MM, 9

ATTORNEYS Patented Dec. 15, 1953 :UNI TED STATES 'PATEN T OF F I C E 2,662,475 FOOT UPERTED HYDRUIIC PMP George W. McLellan, Application June5, 1950, Serial No.l166,232

-2 Claims.

mote from the jack itself.

A still further object of the invention is to of this character which may a relatively low cost, is easily operated and is readily adaptable for various lifting purposes.

With the above and other objects in view which will appear as the description proceeds, my invention consists in the novel features herein set forth, illustrated in the accompanying drawing and more particularly pointed out in the appended claims.

Referring to the drawing in which numerals of like character designatesimilar parts throughout the several views:

Figure 1 is a top plan view of the jack assembly;

Figure 2 is a longitudinal sectional view taken on line 2--2v of Figure 1;

Figure 3 is an enlarged sectional view taken n line 3 3 of Figure 1, showing the relief valve structure; and

Figure 4 is a view in side elevation, showing the jack assembly in folded or collapsed position.

In the drawing, 5` represents the main base of the jack which may be composed of any suitable metal, cast to form a centrally disposed raised portion or annular body 6, recessedv as at 'I' to form the base of a fluid reservoir as will be seen o end of a collapsible piston Bartlesville, Dkla.

respectively.

`Within the cylinder 9, scoping jack sleeves, an inner sleeve l5,

I provide a pair of telenamely an outer sleeve vHl and and the inner sleeve l5, all The upper face of the head AHi is preferably provided with a series of rod 21 which is slidably supported in a collapsible frame or base extension, generally indicated by the numeral 28.

The frame 28 `preferably consists of a plurality of substantially trough-like sections, lonnected thereto by means of a 32 which overlies the U-shaped coupling adjacent ends of said sections and is pivoted to their respective ends as at 33. At the outer end of the frame or eX- tension 23, I provide a foot pedal 34 which is pivotally mounted on the frame as at 35, and extends inwardly over the frame, the underside of said foot pedal being operatively connected to the free end of the pump rod 21 by means of a link pivoted to the foot lever at 31 and to the pump rod at 38.

The pump rod 21 is similarly composed of a plurality of longitudinally jointed sections, the innermost of which 39, is pivoted to the piston stem at as previously described, the next section 43, being longitudinally spaced from the former and hinged thereto by a U-shaped coupling 4I which is connected to the respective rod sections by transverse pivots 42. In order to slidably support the piston rod 21 for reciprocating movement in the frame 23 and at the same time prevent its lateral displacement, I preferably provide a transverse web i3 which extends across one end of the innermost section 29 of the frame, said web being so positioned with respect to the coupling 4I as not to interfere with its reciprocation.

At the operating end of the piston rod 21 the section 4U thereof is provided with a coil spring 44, the inner end of which abuts a xed ring in the frame, with its outer end in engagement with a collar 45 secured to the rod section. lThus upon depressing the foot pedal 34 the rod 21 and the piston 23 are forced inwardly and upon releasing the foot pressure the piston, piston rod and foot pedal are returned to normal position by spring 44.

Returning to the body I5 supporting the reservoir, it will be noted that said body is provided with a passageway 41, placing the inner end of the cylinder 2?. in communication with the pressure well I9 beneath the jack sleeves, a check valve 48 being located within the passage and arranged to permit the injection of fluid from the cylinder into the pressure well I9 but to pre- I vent its ejection therefrom. A branch passage 49 connects the passage 41 with the lower eX- tremity of the reservoir and this passage is similarly provided with a check valve 50 which acts in the opposite direction, that is, the valve 5E), F'

is arranged to permit the withdrawal of uid from the reservoir but to prevent the entrance of fluid therein from the passageway 41.

The operation of the mechanism thus far described is as follows. Upon manipulating the foot pedal the piston rod 21 is reciprocated in the frame 28, which in turn causes the reciprocation of the piston 23 in the cylinder 22. On each return stroke of the piston 23, under the action of spring the reservoir 8 past valve 59, into the cylinder, and is injected into the pressure well I9 through valve 48, when the piston is again advanced by the action of the foot pedal 34, so that repeated operation of the foot pedal causes the uid pressure to build up within the well I9 and the jack sleeves I4 and I5, te elevate the jack head to the desired extent,

rIhe release of the fluid pressure from the jack sleeves and the well i9 for permitting the jack to descend, is effected by means of a relief valve located in the body extension 2| and shown in detail in Figure 3. Here it will be seen that a needle valve 5I carried on a valve stem 52, is reciprocably mounted in an opening in the body 44, fluid is withdrawn from 6 and acts to normally close a restricted passageway 53 which leads into the pressure Well I9. Preferably, a ring 5I' of synthetic rubber or other suitable material is fitted on the needle valve to engage and close the restricted passageway 53 when the valve is thrust inwardly as in Figure 3. A branch passageway 54 connects the passageway 53 with the interior of the reservoir and thus, when the valve 5I is withdrawn, fluid from the well I9 is permitted to ow back through the passageways 53 and 54, and return to the reservoir.

The operating connection for the needle valve 5I is similar to that for operating piston 23 and as will be seen in Figure l, the valve stem 52 is hinged to the first section 55 of the valve stem extension, by a U-shaped coupling 56. A second section 51 of the valve stem is similarly hinged to the opposite end of section 55 by a U-shaped coupling 53. The sectional valve stem is also slidably and rotatably supported in the frame 28 by means of the cross web 43 and the outer extremity of the frame is preferably provided with a bracket 59 for slidably supporting the protruding end of section 51 of the valve stern, which is provided with a handle 6I).

A coil spring 6I is interposed between the handle 5S) and the outer face of the bracket 59 and normally tends to retract the valve stem to open the relief valve 5I. However, the valve may be locked in either open or closed positions by means of a radially projecting pin 62 xed to the stem section 5? and arranged to cooperate with a slot (not shown) in the inner face of the bracket 59. By simply turning the handle to the right or left and pushing the stem inwardly, the pin G2 passes through the slotted bracket 59 to close the valve, said valve being locked in this position by a turn of the handle 69 to bring the pin 32 into engagement with the inner face of the bracket, as shown in Figure l.

To open the valve 5I, the handle is rotated to release the pin E2 which again passes through the slotted bracket under the action of the spring 6I until the pin engages the outer wall of the bracket 59 which limits the outward movement of the valve stem. In this position the valve 5I permits the return of the uid from the well I9 to the reservoir through passages 53 and 54. It may be noted that this is the normal inoperative position of the valve stem which brings the joint 58 to rest adjacent the piston rod joint 4I. Thus, when the assembly is to be folded, the handle E0 must be rotated to bring the pivots of the joint 58 into proper transverse alignment with the respective pivots of the rod joint 4I and the frame joint 32.

My improved arrangement of jointed piston rod, valve stem and supporting frame, affords a convenient means of inserting the jack assembly in positions of difficult accessibility by using the frame as a means of locating the jack. Furthermore, the jack may be operated at a considerable distance from the point of elevation and when not in use the entire assembly may be conveniently collapsed for storage. As shown in Figure 4, the outer section 3| of the frame is folded on to the inner section 29 by means of the joint 32 and the inner section 29 is folded upwarclly on the hinges 30, the sectional piston rod and valve stem being simultaneously folded by means of their respective hinge connections. As before indicated, the hinged couplings of the piston rod and the valve stem are so located and adjusted with respect to each other and to the assembly can be folded Without diiculty.

From the foregoing it is believed that my invention may be readily understood by those I claim: 1. In a pump including a base, a horizontal pump cylinder mounted 1n fixed relation on said 6 eratively connected to the adjacent end of said rod, said frame and piston rod being simultaneously extendable from said base to a horizontal operating position.

2. A device as claimed in claim 1 including a release valve in said base, communicating with said cylinder and a collapsible valve-actuating stem pivotally connected thereto and formed of a series of sections hingedly connected in end-toend relation, at points normally lying adjacent corresponding hinge connections of said frame and piston rod, said Valve-actuating stem being slidably supported in said frame and simultaneously extendable from said base, with said frame and piston rod.

GEORGE W. MCLELLAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 83,065 Hoyt Oct. 13, 1868 1,570,071 Mercier Jan. 19, 1926 1,665,633 McDonell Apr. 10, 1928 2,161,053 Inman June 6, 1939 2,173,598 Sonderup Sept. 19, 1939 2,471,770 Noble May 31, 1949 2,567,681 Schwartz et al Sept, 11, 1951 2,577,539 Page Dec. 4, 1951 FOREIGN PATENTS Number Country Date 255,600 Switzerland Feb. 16, 1949 

